How do I check amount of particles striking detector surface

I’ve been running 87000 events and was trying to figure out how to determine the amount of particles that are hitting in the simulation

Hi @Aatuser

for every particle that interacts with the detector, one MCParticle is generated. Assuming you have stored those using the ROOTObjectWriter, this ROOT macro should do the job:

// Open tree
TTree* mcp_tree = static_cast<TTree*>(file->Get("MCParticle"));
// Get branch of the detector of interest
TBranch* mcp_branch = mcp_tree->FindBranch("my_detector");
// Bind the information to a predefined vector
std::vector<allpix::MCParticle*> mcparticles;

size_t total_particles = 0;
// Loop over tree, event-by-event:
for(int i = 0; i < mcp_tree->GetEntries(); ++i) {
    total_particles += mcparticles.size();
std::cout << "Total particles: " << total_particles << std::endl;

Best regards,